Bama (Bama) flexifer, McAlpine, 2015

McAlpine, David K., 2015, Signal Flies of the Genus Bama (Diptera: Platystomatidae) in Papua New Guinea, Records of the Australian Museum 67 (2), pp. 25-53 : 32-33

Bama (Bama) flexifer n.sp.

Figs 7–10

Type material. Holotype ♂ (unique). Eastern Highlands Province: South Wanitabe, near Okapa , 5000–6000 feet [c. 1500–1830 m], 13.xi.1964, P.H. ( ANIC).

Description (♂, ♀ unknown). Slightly elongate blackish fly, with wing heavily marked, mainly anteriorly to vein 4. Coloration. Head largely brown-black, with silvery pruinescence on postorbital to postgenal zone. Antenna tawny with brown arista. Prelabrum dark brown; palpus largely tawny, brown basally. Thorax dark brown. Legs: coxae brownish; mid coxa with most setulae black; femora dull yellow, becoming brown distally; tibiae and tarsi brown to dark brown. Wing ( Fig. 8 ) anteriorly to vein 4 largely brown-black; first costal cell and sub-basal zone in second costal cell yellow; first basal cell with two hyaline zones; first posterior cell with posterodistal hyaline zone, but brown zone of this cell extending posteriorly to enclose discal crossvein; discal cell otherwise without brown zones; halter pale yellow. Abdomen shining black.

Head. Postfrons apparently similar to that of B. signifer ; height of cheek 0.18 of height of eye; face rather strongly concave in profile, except on slightly convex lower marginal zone; fronto-orbital bristles moderately short; postvertical bristles present but minute. Antennal segment 3 c. 1.7× as long as deep; segment 4 short; segment 5 apparently slightly longer than its maximum diameter; segment 6 ( Fig. 10 ) gradually tapered beyond bare basal section, thence with well-developed pubescence for rest of length. Prelabrum deep and prominent; palpus much longer than in B. signifer (comparing opposite sexes), slightly spatulate.

Thorax generally as described for B. signifer , but prescutellar acrostichal bristle present, c. as large as dorsocentral bristle. Fore femur with rather slender posteroventral bristles and less developed posterodorsal bristles; hind basitarsus distinctly shorter than in B. signifer (female); mid coxa resembling that of B. signifer , but with more numerous fine black setulae on distomedial lobe. Wing: much of first costal cell and entire second costal cell microtrichose; section of costa between costagial break and humeral break more thickened than in other species; stem vein with several minute dorsal setulae; vein 2 with strong flexure near mid-length, so that submarginal cell is markedly broadened from level of anterior crossvein; second section of vein 4 almost straight; penultimate section of vein 4 slightly longer than anterior crossvein, c. half as long as discal crossvein; anal cell, large part of second basal cell, and basal hyaline zone in first basal cell bare; anal crossvein strongly curved near anterior end, with concave curvature on rest of extent.

Abdomen. Condition of sternite 4 not known; aedeagus ( Fig. 9 ): preglans simple, not markedly expanded or spinulose; flexible section little developed; glans subcylindrical, with large membranous distal lobe; bulb elongate, slightly shorter than glans; terminal filaments elongate, right one c. as long as glans, left one c. twice as long.

Dimensions. Total length, 4.3 mm; length of thorax, 2.2 mm; length of wing, 5.5 mm; length of glans of aedeagus, 0.29 mm.

Notes. Bama flexifer has the wing pattern ( Fig. 8 ) most resembling B. signifer , but the uniformly short-haired (or long-pubescent) arista is very different from that of B. signifer .

The specific epithet is a Latin compound noun, flexurebearer, referring to the course of vein 2.

Figures

Figures 7–10. Bama flexifer n.sp., holotype male. (7) Head. (8) Left wing. (9) Distal part of aedeagus, scale = 0.3 mm. (10) Right arista (basal segmentation unclear).bu, bulb;fs, flexible section of aedeagus; g, glans; lg, distal lobe of glans;pg, preglans;tf, terminal filaments.